January 16, 2014

Researchers Develop Method For Authenticating Premium Chocolate

The taste of a rich, thick morsel of luxurious premium chocolate can be the ultimate experience for some people. But how do you know you are getting what you paid for? Until now, chocolate connoisseurs had no way of knowing, other than their own taste buds, whether they were getting the real deal.

A new study, published in the American Chemical Society's (ACM) Journal of Agricultural and Food Chemistry, reports that a method to authenticate the varietal purity and origin of cacao beans -- the source of chocolate's main ingredient, cocoa—has been developed for the first time.

Lower-quality cacao beans often get mixed in with premium varieties on their way to becoming chocolate bars, truffles, sauces and liqueurs, said Dapeng Zhang, postdoctoral researcher at the National Center for Biotechnology Information. However, the stakes for policing the chocolate industry are high because it's a multi-billion dollar global enterprise. In some areas, being a chocolatier is as much an art form as a business. Conservation also plays a role in knowing whether products are truly what the confectioners claim them to be in that the ability to authenticate rare varieties would encourage growers to maintain cacao biodiversity rather than depend on the most abundant and easiest to grow plants.

Using genetic testing, researchers have discovered ways to verify the authenticity of many other crops, such as cereals, fruits, olives, tea and coffee. However, these methods are not suitable for cacao beans, leading Zhang and his team to address the challenge of finding alternative methods.

The team applied the most recent developments in cacao genomics to identify a small set of DNA markers known as SNPs (pronounced "snips"). These SNPs make up unique fingerprints of different cacao species. The team found that the technique works on single cacao beans and can also be scaled up to handle large samples quickly.

"To our knowledge, this is the first authentication study in cacao using molecular markers," the researchers state.